W5R2 - what's the point?

Well I was very happy with W5R1 and found running for 5 mins was OK - so much so that I then inserted a 'special' run of my own on Monday to prove a theory about run/walk/run calculating that 4x 5:30 runs @ 4:40 mins per km pace interspersed with 3x 1:00 fast walk should produce a sub-25 minute 5k, which it did and I covered 5k in 24:08 according to my app.

So I came to W5R2 last night which is 2x 8 mins with a whopping 5 min walk in between. I just don't get it. Obviously there is a progression from running for 5 to running for 8 mins but having such a huge break in between did not seem helpful, especially when in 2 days time I am supposed to run non-stop for 20 minutes. That is a HUGE progression and I am tempted to insert another 'special' of 14 mins run / 1 min walk / 6 mins run before I attempt W5R3.

How did others feel about the progression of the W5 runs?